Engineered Multilayer Colloidal Crystals with Tunable Optical Properties

Multilayer colloidal crystals with a perfectly defined architecture have been fabricated by the successive depositions of layers of silica particles with various diameters onto a substrate. The composite materials have been characterized by scanning electron microscopy (SEM) and near-infrared (NIR) spectroscopy. Our results establish that the optical properties of these multilayer systems can be tailored by adjusting either the thickness or the stacking order of each component crystal. The versatility of our approach has been further exploited to fabricate a multilayer colloidal crystal consisting of many alternating layers of two different spheres sizes.